Desalting crude oil



c. G. KIRKBRIDE Y|51- AL Nov. 23, 1948.V

DESALTING CRUDE OIL 2 Sheets-Sheet 1 Filed Oct. 4', 1945 Patented Nov.23, 1948 a OFFICE A n i l l 2,454,605@V f DESLTING CRUDE OIL ChalmerfG.l Kirkblide, CollegefStation, l and Mark Y Hopknsy. "Iexas-Gity, Tex., lassignors to .Pan `AmericaneRefining Corporation, New York),

N( YL; a corporation of Delaware Application Octulzaer` 4,1945glSerialfN. 6203421 This f i'nVentionl" relates :tor` improvements*irri` the' desaitingi of `salt-contaihingioleaginouslicniids and moreparticularly"relates toV the desaltingi'of hy-" l erallyfemulsified intheioil lto varyingdegrees. and.

may rangef-from ya practically hfreshnon-saline water. torbrinensolution.almost saturated: with.l in-` organic salts,.especiallyfchloridesJotsodium,l cal-V ciurrrland.` magnesium; Sincet the salt contenti inmosti' crude oils'` is l present afs highly dispersed? -l brine; the:emulsions tf'ormedfaresingeneral ofthefweiterem-0111typen, Theseemulsionsare stabilized can be 4effectively desalted, and-emulsions ofsuch liquids with salt Water-canbe'resolved by passing such-liquidsthrough: a compressed bed of fiber curring'fstabilizing or 'emulsifyingagents which are v and/ or resolvingufemulsions Toi" oleagincus iliquidzsi and-salt Water Anotheriobje'ct of"the"invention is toprovidefa method of desaltig crude petroleurn-foil?" Anotherobjectfof'the-inventionisvtoprof Vide a met-hod" ofi resolving emulsionsof crude oil and salt Water.; l. l

`Other objects and advantages ofi the invention iXi-ill become-'apparentfrom tlietfollowing description thereoffrea'din conjunction with theaccompanying drawingsin which f Figur-e 12: isa;diagrarmnaticov'vlldiagrami of a preferred? embodiment of :theinvention.

`Figure 2is? a sectional-lelevationof one form of lter bedand settlerused in carrying out the process oftheinvent'ion.

Eigure 3 isfafront elevationofthefsettle shown imFigure' 2.;1a.n"d`:

. compressing the bed it willbe' found that the iii-- glass.-`Thebedofber glass may be'inrthe form uffa single mass oflfiber glass ormay take-the form of multiplerelativ-ely thiirbeds. of the. ber glass-.-Although not essentiallgit is preferablegthat passage. of4 theliquid-through the bed ciA berlglass, be followedv` by passage=throughabed of-gravevl or sand or" the equivalenti-such as Yfor example-alayer-15-30 rnesh-sandfsupportedr on a= bedof. one# eighth to one-quarterinch-gravel.. I v K v 4 For they most effective resultsftheberglass2bedr should havea. density ofrfrromtaboutlOlpounds to, about VM210.-pounds percubicf foot and.: an Vinteri-lloer. distances based on-,suehbedl densities, ofl from about-0:0042. inch toA about!)084inch.v An. exfposed fiber-aldeam of .from about` 2.2.. to *l about .4.4 square-feetpergallnl oifoilftreated piervhour is desired for optimum effectiveriessfheseiactorszv are obivza-ineclrwhen1 usingea fiber withad-iameterof.00028 inch? Suitable berglassfor the' hereindescribed: purpose isthefi-lb'er glassl"1r/1arketedf by` the.' Owens-Corning ,FiberglasfCorporation?, althoughit is,tobe:understood 4thai-any fiber glasshaving.theldesiredproperties aboyedesoribedcan ber-employed. ByWay"oi-exampleY l the yfolloizvilng produetsmarketed` by, theOWenseC'orning Fiber-vv glas-fCorporationvor..even-smaller fibersaresuitable, l

Averagev Fiber Fiber No. Diameter, Inches to anchor lthe n bers andprevent" channeling through? the bed due tolshi'fting offtlfieribers.yin

it'ial compression isi ratlier elasticfanduniform until a density ofabout 9 pounds/entita. isreached.

, Thereafter, the `bed becomes "relatively" incom-l pressible unlessspecial provisions' are-made to perfratedf `plate.'@Intigeneral;compessiorirmusti be earifieds'uiciently beyondthe point ofi apparentincompressibility so; that thefnal density'willzbe increased by atleast.,1'0 an'dLpreferably by: 25%.v Itiwiilbeevident thatfsufcientcompression: isnnot attanablebyfordinarymeansesueh:asftampingfor.

3 by compression between relatively flexible members,

As alluded to above, it is advantageous to provide a gravel or sand bedfollowing the bed ci fiber glass. The sand or gravel used in such bedshould be of relatively coarse grain, such materials of from 16 to 60and 4 to 8 mesh having been found suitable.

Before the salt-containing oil is passed through 4 charged line. Themixture of crude oil and water is introduced via line 20 into the top ofa lter cell 2| provided with a fiber glass bed 22, superimposedupon agravel bed 23. If desired, an orifice mixer designed for a pressure dropof 10 to 50 pounds may be advantageously interposed in line 20.,vAfter.- passing through the filter cell the mixture of crude oil andwater is introduced into a settling chamber 24, provided with a bafflethe fiber glass bed, it is preferable to introduce into 10 Zone asherein-described, wherein stratification the salt-containing oil fromabout 2% to about of the water and desalted crude oil takes place. 25%and preferably from about 5% to about 10% y The desalted crude oil isremoved from the settler of fresh water, and to heat themixture t0 ateml 24 through line 25, while the water is removed perature of fromabout 150 F. to about 300 F. and "from the settler through line 25.preferably from about 200 F. to about 250 F. T15 1 A suitable filtercell and settling chamber well While the feed rate to the filter can bevaried adapted for the herein-described purpose is within wide limits,it has been found that 'shown in detail in Figures 2, 3 and 4. Referringfor fiber glass filter beds having the above deto Figure 2, the filtercell 2| is equipped with scribed characteristics, .the feed rate to suchthree perforated plates 28, 29 and 3D, providing beds should not exceedabout 1200 barrels 23 fiber glass bed 22 and agravel bed 23 The pelfO-per day per cubic foot of compressed fiber rated plates 2S and 30 arefixed in the cell 2l while glass, and is suitably within the range ofthe perforated platel28 rests upon the ber glass from about'100 to about'750 barrels per day per bed. By means of screw bolts 3i, which actsquare foot and preferably from about 250 to about against holding means32, pressure on the perfo- 400 barrels per day per square foot when thetotal 25 rated plate 28 can be regulated to give the dethickness of thebed is 11/2 toinches. sired density to the fiber glass bed. The set-After the salt-containing oil is passed through tling chamber 23comprises a horizontal shell 33 the filter bed, the oil and water isintroduced into divided into an unbaifled Zone '34 and a baiile zone asettler drum which is suitably provided with a 35. The baffle settlingzone is equipped with non-baffle Zone and a baiiie zone. The baffle zone30 horizontal bailies 38 mounted in a frame 31 supcan be provided withlongitudinal bailles mountported on a shaft 3S passing through bearings39 ed in a frame on a shaft so that the plane of the and lill. The shaft38 is coupled with an arm 4l baille plates can be varied from thehorizontal which extends to the exterior of the shell 33 to the Verticalby rotating the shaft, thus perthrough a stuffing box 42.' The free endof the mitting variations in the settling distance at con- 35 arm il isattachedV to a disc? 43 which is provided Stant retention times. Theretention time in the with a lever i4 to facilitate the rotation of thesettler can be varied over a wide range, although baffle frame 37. Thebaffles 35 can be adjusted retention times of from about 2 minutes toabout to the desired position'by rotating the shaft 38 by 20 minutes ormore are suitable, depending on means of lever 44 and iixing the bafflesin the the settling distance. 40 desired position byV suitable securingmeans, such An application of the present invention is as by inserting apin into one of the openings i5 given by the following description whichis given v (Figure 3) in the bottom portion of plate 43. By by way ofillustration only andis not intended to rotating the baiile frame, theplane of the baflle be a limitation to the scope 0f the invention.Replates can bevaried from the horizontal to the ferring to Figure 1, asalt-containing crude oil 4,5 vertical, thus permitting variation of thesettling from a storage tank I0 is pumped via a pump Il distance at a,constant vretention time. and line I2 through a preheater i3 wherein thefThe crude oil desaltingeciency of fiber glass crude oil is heated to atemperature of yabout having theI herein-described characteristics is250 F. From the preheater, the heated oil is illustrated by data in thefollowing data:

Table I Contact Bed Temp. F Salt Content Run lgura- OilIlper Ps'srgpScttler No 1011, Density, sq. ft. per .Across Bed Press., 1 bs. Charge,Treat., Y

H igea ist." Der' lbs-5,4 D mm- Se 5.23. i3 i3- irait Bbl Bbl.

32 Fiberglass. 12.5- 5 14.2 266 23 25 202 100 24.0 vTrace 100 16 o 12.55v 14.2 320 30 25 200 157 21.2 Trace 100 10 12.5 k5 14.2 390 39 30 202100 21.2 kTrace v100 15 12.5 5 14.2 440 50 35 200 185 21.2 Trace 100 3512.5 5 14.2 406 63 35 205 192 21.2 Trace 100 5 6.25 2.5 14.8 266 10 35206 190 27.2 Trace 100 5 6.25 2.5 14.8 406 24 25 204 192 27.2 v 0.3 99 93.75 1.5 14.8V 266 12 35 204 190 27.2 1.5 94.5 4 3. 75 1.5 14.8 496 20a5 200 138 v '27.2 8.7 68.0 255 22g 370 54 35 200 190 Y38.0 6.3 33.54...-. 16 475 15 266 10 )25 205 190 17.5 13.5 22.0 5 475 15 496 10. 25.206 195 18.2 14.2 22.0 2 475 15 71o 10 25 204 194 13.2 16.0 12.0

passed through line Hi through an oil meter l5 7 0 and into the line I6where it is mixed with water introduced via pump H and line i8. Line I8is provided with a water meter I9. The amount of water introduced intoline l1 is so regulated Run No. 1 was of 108 hours duration. The bedconsisting of 121/2 pounds of Pyrex No. '719 fiber glass, Vpacked infive individually supported one inch layers. The average diameter ofPyrex No. 719'f1ber glass isl withinfthe'range of from about as tointroduce ab0ut.10%. of fresh water into the 75 0,0002v to 0.0003111611withan average diameter acrossthe bed; i A'lmost` complete" water`separationwasobtained' with a retention timeas low as y 6:3"jminuteswith' "watersettling rates as high as 2.155` inches'` per minute-.beingobtained:

was madeto compare the degree of desalting obtainable withvaryingamounts offiber glass.

Using" first' five one-halfunch' beds of Pyrex No; 71'9"`fibe`r glass,complete desalting 'waspbtaincd at 26.6 and.496.barrels.of. oil mr.square foot per4 day;` The two toplayers Werethenremoved leaving threeone-half'inchla'yers: Undertheseconditions 94.5% and 68%.1 salt`removal.wasobtainedl at266 and'496barrel's persquarefoot per day,respectively: i

Run No. 3. wasJmade. with `a combination or` a;berglassbedpandasandlbed; Thisbed'was built up of alternate layers' ofsandjand fiber' glass in which a seven"in,ch"layer. of sand was covered.with. a.thr.ee .inch' layer.. off ber. glass. TheY corn-` pletebed`was.about.l0jinchesdeep and contained 225 poundsof san'dan'd4 poundsof fiber glass. This run was of Z55-hours yduration at avconstant rateof 370 barrels of crude oil per square foot per'day. fFor-theifi'rst1-70 hours the pressuredrop across the bed rose from401to.50f`pounds1per square inch; from. 17.0,v hoursto 200 hours thepressure drop increased 56 pounds, and at 255 hoursthe pressure droproseto 86 pounds per square-incl`n Aseshown 'by'vthe data, goodsaltremoval-was1obtained RunNo'ewa-s made-onailterbed consistingcompletelyiof sand. As-s-how-nby-the datalin the above-table; verypoorsalt removaliwas obtained.

Referring-torunNo. 2 it'wllbe notedthat the degreeof: salt removalisdependent on the filter rate at a given.total;bedrtlniclrnessf Ingeneral, it isr contemplated that a total bed depth ofat leastilL/g'" beused when'nlering at aV rate of 300 b./d. per sq.' ft'." Wlienthicker orthinner-*beds are used the filter rate may be increased or decreasedproportionately. For example, when using a bed `1/2 thick, a filter rateof about 100 b./d. per sq. ft. will be satisfactory for eflicient saltremoval.

Although multiple beds of glass wool have been cited in runs No. 1 andNo. 2, a single bed may be used, particularly when the amount of solidspresent and consequently the rate of pressure drop increase, is Verysmall. When solids are present, the single bed is subjecttodisintegration due to the fact that the lower part of the bed mustsupport the entire drop in pressure. By using multiple beds, thepressure drop is divided between the beds and a much higher total finalpressure `drop can be tolerated before disintegration occurs. Anotheradvantage of the multiple bed arrangement resides in the ability toreplace the initial beds without disturbing the latter beds whenundesirable pressure drop has developed. When multiple beds are used,they should be independently compressed and supported.

With multiple beds, the glass liber size may be graded to permitoperation for a longer period of time before excessive pressure drop isdeveloped. For example, the rst bed may be made of fiber glass having anaverage ber `diameter of about 0.00055 inch, the second bed of fiberhaving an average diameter of about 0.00040 inch, and succeeding beds ofber having an average diameter of about 0.00022 inch or even finerfibers. In general ber having an average diameterof` about'0i0004`0 inchor smalleriispreferredi in making' up the beds.` In this manner, thelgreater interstitial distance betweenw bers in the first bediwillipermit accumulation of 'agreaterl arnountof solidssorwill collectthe Ylarger sized solids and thereby'prevent"pluggingof the =bedsf of'nnenbersize: -In some-cases it may bede-1l siraolei topassthe emulsionsfirst through a sand bed'arranged to permit backwashing invordertoremove thebulk of* thesolidmatter; and thereby prolong the 'life ofthe glass-fiber filter. Manyf alternate" arrangements `will be evident'to` those skilled inthe art'.

thefidesaltin'g process.

Basically, passagefof the water-in-oil emulsione through the fiber glasscauses the exceedingly# smalliwatejr and* brine droplets -to coalesceinto relatively-large driopswhi'ch' separate readily. In! arsmuch-asglass' is' a silicious material, it isf pref-J1- eren'tially'wetted bythe aqueous phaseand ther'ebyifis able to 'collctaqueous droplets untilthey becomef-large enoughto be eithersweptaway 'by the moving oil"stream' in'4 relativelylarge-sizedii dropsor to fallfrointhe-wet-tedm'ass. @In this: processthe `interberdistance plays animportant riolefinassuring` the contact betweenA ra droplet andlia-`=glassbe'r; Although decreased interfiber* distances"may'be` usedwhenemploying finer bers with'l extreme compression' of the bed; effectiveYdesaltinglcan beobtained,A within limits, by usi-iigv relatively'coarser liber and increasing 'the-depth'r of i the lbedr In `additintoVthe preferential wettingpoweroff the glass fibers,V thereisf thepossifibersA generates-` an electric'vcharge -on the Y droplets-lwhichhi facilitates coalescence. While the exactfreasons fontheeffectiveness ofl the com-- pressed glass wool fibers is not knownprecisely, it is believed that all the aforementioned factors play somepart in this process.

The type of lter used may be similar to that shown or may be constructedas a separate unit. For example, two filters may be made similar to theKelly Type multiple leaf filter, and arranged to permit the use of onefilter While the other is being b'ackwashed or recharged with freshglass wool bers. By the use of such lters, an extremely large filterarea may be contained in a vessel of small volume. Provisions may alsobe -made for adding a filter-aid precoat for collecting foreign materialand prolonging the life of the glass wool. A cylindrical arrangement mayalso be used in which the emulsion passes from the outside throughlayers of glass Wool compressed between perforated cylinders, into thelcenter of the filter.

Although the invention has been described in detail with regard topreferred procedures and in reference to certain preferred materials andproportions, it is to be understood that variations and modificationstherein are possible Without departing from the spirit and scope fof theinvention as deiined by the following claims.

We claim:

1. The method of desalting brine-containing oleaginous liquidscomprising passing a brinecontaining oleaginous liquid through a bed offiber glass, said bed having a density of from about 10 pounds to about20 pounds per cubic foot and an interfiber distance, based on such beddensities,V

. 3. The method of desalting a salt-containing oil comprising passing asalt-containing oil successively through beds of fiber glass and beds ofgravel said fiber glass having a density of from about 10 pounds toabout 20 pounds per cubic foot, an interiiber distance, based on suchbed densities, of from about 0.0042 inch to about 0.0084 inch, and anexposed fiber area of from about 2.2 to about 4.4 square foot per gallonof oil treated per hour, and said gravel being from about 4 to about 8mesh.

4. The method of resolving a crude oil-salt water emulsion and ofvdesalting said crude oil comprising introducing from about to about 10%fresh Water into an emulsion vof crude oil and salt Water, heating saidemulsion to a temperature of from about 150 F. to about 300 F., passingsaid mixture directly through a fiber glass bed l having a density offrom about 10 pounds to about pounds per cubic foot and an interberdistance, based on such bed densities, of from about 0.0042 inch toabout 0.0084 inch, introducing the filtrate from said filter ibed into asettling chambervvherein said oil and said Water are permitted tostratify, and separately withdrawing said Water land said oilsubstantially free of salt.

5. The method of desalting crude oil comprising passing asalt-containing crude oil at a temperature of about 200 F. t-o about 250F. through a ber glass bed comprising a plurality of layers of ber glasshaving an :average diameter within the range of from about 0.0002 toabout 0.0003 inch,

said fiber glass bed having a total depth of about 5 inches and adensity of about 14.2 pounds per cubic foot.

6. The method of desalting a brine-containing crude -oil comprisingpassing a mixture of brine and crude oil through a filter bed of fiberglass consisting of bers having an average diameter smaller than about0.00055 inch and compressed to a density in excess of ten pounds percubic foot, said brine-containing oil being passed through said bed at arate not exceeding about 1200 barrels per day per cubic foot ofcompressed fiber glass.

7. The method described in claim 6 in which the crude oil is preheatedtoa temperature of from about F. to about 300 F.

8. The method described in claim 6 in which from about 5% to about 10%fresh Water is added to the brine-containing crude oil.

9. The method described in claim 6 in which the filtrate from the filterbed is settled to permit stratication of the oil and Water andseparating the salt-free oil from the Water.

CHALMER G. KIRKBRIDE. MARK C. HOPKINS.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS OTHER REFERENCES Scientific American, Dec. 11,1920, vol. 123, page 593; Filtering :by Means of Spun Glass.

